NavigationView Handler for Android (#2336)

* NavigationHandler Android

* - code cleanup

* - cleanup

* - cleanup code

* - fix naming

* - fix comments

* - move toolbar code to controls

* - code cleanup

* - organized code into NavigationManager

* - cleanup

* - cleanup

* - add to gallery

* - update naming

* - fix winui

src/Compatibility/Core/src/Android/VisualElementExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using Microsoft.Maui.Controls.Platform;
 using Microsoft.Maui.Controls.PlatformConfiguration.AndroidSpecific;
 
 namespace Microsoft.Maui.Controls.Compatibility.Platform.Android

src/Compatibility/Core/src/Windows/NavigationPageRenderer.cs

@@ -171,11 +171,11 @@ public void SetElement(VisualElement element)
 				throw new InvalidOperationException(
 					"NavigationPage must have a root Page before being used. Either call PushAsync with a valid Page, or pass a Page to the constructor before usage.");
 
-			if (oldElement != null)
+			if (oldElement is INavigationPageController navigationPageController)
 			{
-				oldElement.PushRequested -= OnPushRequested;
-				oldElement.PopRequested -= OnPopRequested;
-				oldElement.PopToRootRequested -= OnPopToRootRequested;
+				navigationPageController.PushRequested -= OnPushRequested;
+				navigationPageController.PopRequested -= OnPopRequested;
+				navigationPageController.PopToRootRequested -= OnPopToRootRequested;
 				oldElement.InternalChildren.CollectionChanged -= OnChildrenChanged;
 				oldElement.PropertyChanged -= OnElementPropertyChanged;
 			}
@@ -218,9 +218,14 @@ public void SetElement(VisualElement element)
 					Element.Appearing += OnElementAppearing;
 
 				Element.PropertyChanged += OnElementPropertyChanged;
-				Element.PushRequested += OnPushRequested;
-				Element.PopRequested += OnPopRequested;
-				Element.PopToRootRequested += OnPopToRootRequested;
+
+				if (Element is INavigationPageController newPageController)
+				{
+					newPageController.PushRequested += OnPushRequested;
+					newPageController.PopRequested += OnPopRequested;
+					newPageController.PopToRootRequested += OnPopToRootRequested;
+				}
+
 				Element.InternalChildren.CollectionChanged += OnChildrenChanged;
 
 				if (!string.IsNullOrEmpty(Element.AutomationId))

src/Compatibility/Core/src/Windows/VisualElementExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using Microsoft.Maui.Controls.Platform;
 using Microsoft.Maui.Controls.PlatformConfiguration.WindowsSpecific;
 
 namespace Microsoft.Maui.Controls.Compatibility.Platform.UWP

src/Controls/samples/Controls.Sample/Pages/Core/NavigationGallery.xaml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<views:BasePage 
+    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    x:Class="Maui.Controls.Sample.Pages.NavigationGallery"
+    xmlns:views="clr-namespace:Maui.Controls.Sample.Pages.Base">
+    <views:BasePage.Content>
+        <StackLayout
+            Margin="12">
+            <Label Text="Page Count" x:Name="lblPageCount"></Label>
+            <Button Text="Insert Page Before Current" Clicked="InsertPage" />
+            <Button Text="Pop Page"  Clicked="PopPage" />
+            <Button Text="Push Page"  Clicked="PushPage" />
+            <Button Text="Remove Page Before Current"  Clicked="RemovePage" />
+            <Button Text="Pop To Root"  Clicked="PopToRoot" />
+            <Button Text="Swap Root"  Clicked="SwapRoot" />
+            <Button Text="Toggle Navigation Bar"  Clicked="ToggleNavigationBar" />
+            <Button Text="Toggle Back Button"  Clicked="ToggleBackButton" />
+        </StackLayout>
+    </views:BasePage.Content>
+</views:BasePage>

src/Controls/samples/Controls.Sample/Pages/Core/NavigationGallery.xaml.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Maui;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Graphics;
+
+namespace Maui.Controls.Sample.Pages
+{
+	public partial class NavigationGallery
+	{
+		static int pageCount = 0;
+
+		static List<Page> _currentNavStack;
+		public NavigationGallery()
+		{
+			InitializeComponent();
+			pageCount++;
+			lblPageCount.Text = $"{pageCount}";
+			this.Title = $"PAGE NUMBER {pageCount}";
+		}
+
+		void InsertPage(object sender, EventArgs e)
+		{
+			Navigation.InsertPageBefore(new NavigationGallery(), Navigation.NavigationStack.Last());
+		}
+
+		async void PopPage(object sender, EventArgs e)
+		{
+			await Navigation.PopAsync(true);
+		}
+
+		async void PushPage(object sender, EventArgs e)
+		{
+			await Navigation.PushAsync(new NavigationGallery(), true);
+		}
+
+		async void PopToRoot(object sender, EventArgs e)
+		{
+			await Navigation.PopToRootAsync(true);
+		}
+
+		void RemovePage(object sender, EventArgs e)
+		{
+			if (Navigation.NavigationStack.Count >= 2)
+				Navigation.RemovePage(Navigation.NavigationStack[Navigation.NavigationStack.Count - 2]);
+		}
+
+		void ToggleNavigationBar(object sender, EventArgs e)
+		{
+			NavigationPage.SetHasNavigationBar(this, !NavigationPage.GetHasNavigationBar(this));
+		}
+
+		void ToggleBackButton(object sender, EventArgs e)
+		{
+			NavigationPage.SetHasBackButton(this, !NavigationPage.GetHasBackButton(this));
+		}
+
+
+		void SwapRoot(object sender, EventArgs e)
+		{
+			if (_currentNavStack == null)
+			{
+				_currentNavStack = Navigation.NavigationStack.ToList();
+				(Parent as INavigationView).RequestNavigation(
+				new NavigationRequest(
+					new List<NavigationGallery>
+					{
+						new NavigationGallery()
+					}, false));
+			}
+			else
+			{
+				(Parent as INavigationView).RequestNavigation(
+				   new NavigationRequest(_currentNavStack, true));
+
+				_currentNavStack = null;
+			}
+		}
+	}
+}

src/Controls/samples/Controls.Sample/ViewModels/CoreViewModel.cs

@@ -30,6 +30,9 @@ protected override IEnumerable<SectionModel> CreateItems() => new[]
 			new SectionModel(typeof(ModalPage), "Modal",
 				"Allows you to push and pop Modal Pages."),
 
+			new SectionModel(typeof(NavigationGallery), "Navigation Page",
+				"Play with the different Navigation APIs."),
+
 			new SectionModel(typeof(SemanticsPage), "Semantics",
 				".NET MAUI allows accessibility values to be set on user interface elements by using Semantics values."),
 

src/Controls/src/Core/Controls.Core.csproj

@@ -19,14 +19,10 @@
     <AndroidResource Include="$(AndroidRoot)Resources\Layout\flyoutcontent.axml" />
     <AndroidResource Include="$(AndroidRoot)Resources\Layout\shellrootlayout.axml" />
     <AndroidResource Include="$(AndroidRoot)Resources\Layout\shellcontent.axml" />
-
-
     <AndroidResource Include="$(AndroidRoot)Resources\anim\enterfromleft.xml" />
     <AndroidResource Include="$(AndroidRoot)Resources\anim\enterfromright.xml" />
     <AndroidResource Include="$(AndroidRoot)Resources\anim\exittoleft.xml" />
     <AndroidResource Include="$(AndroidRoot)Resources\anim\exittoright.xml" />
-
-
     <AndroidResource Include="$(AndroidRoot)Resources\values\strings.xml" />
   </ItemGroup>
 	<ItemGroup>